Their lawyer argued there was no violence or aggression in their actions, and they were "diplomatic and respectful" at all times.

All 11 were each granted spent convictions, fined $50 and ordered to pay costs of $77.

The protesters - who identify with a variety of churches including Churches of Christ, Riverview, Baptist, Uniting and Anglican - said at the time of their arrest that they were protesting against the treatment of more than 1100 children in Australia's immigration detention centres.

Similar action was also held in the offices of the immigration minister, the federal opposition leader and the prime minister.

The protesters said opposition spokesman for immigration Richard Marles and WA senator Sue Lines welcomed the sit-in participants to a meeting to voice their concerns.

Outside court, Anglican priest Christopher Bedding, one of the protesters, said they were treated with dignity and respect by police and the law.

"We were given the opportunity to have our voice heard, but who will hear the voice of these children?" he said.

"Who will listen to the voice of the children locked up in immigration detention?"

Fr Bedding called for the immediate release of all children in immigration detention, some of whom were suffering rotting teeth, fungal infections and mental illness.

He said the group did not regret their actions, which had started a dialogue among Australians, and had been prepared to go to jail.